JPS62252570A - Magnetic recorder - Google Patents

Abstract

PURPOSE:To prevent the adsorption between a slider and a disk by rotating a disk to a fine angle at a low speed by a signal input to rotate the disk and rotating the disk at a high speed when the then motor electric current is a set value or below. CONSTITUTION:The adsorption force between a disk 1 and a slider 3 is decided by the size of the motor electric current of a spindle 2, when the motor electric current is larger than the set value at the first stage, the disk 1 is positively rotated and reversely rotated to a fine angle only at a low speed, at such a time, the slider 3 is inclined to the disk 1 surface and the contacting area of the slider 3 and the disk 1 becomes smaller. Consequently, the film of the water particle between the slider 3 and the disk 1 is also coagulated to one side in accordance with the inclination of the slider 3, the adsorption force can be reduced, when the adsorption force is not decreased and the motor electric current is higher than the set value in the condition, the disk 1 is rotated at a low speed as the third stage and the relative sliding between the disk 1 and the slider 3 occurs.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a magnetic recording device.

[Prior Art] Fig. 3 is a perspective view showing a conventional magnetic recording device, in which (1) is a disk for recording information, and (2) is a spindle for rotationally driving the disk (1). ,(3
) is a slider equipped with a magnetic core that records and reproduces information on the disk (1), (4) is this slider (3)
a suspension seal for pressing the disc (1);
(5) is an arm that supports suspension gear (4);
) are floating shafts that rotatably support arm (5), (7) and (8
), (9) are a coil, a yoke, and a magnet for moving the slider (3) in the radial direction of the disk (1) by rotating the arm (5).

Next, the operation will be explained. Several disks are mounted on top of each other on a spindle (2) that rotates the disk (1), and are driven at a high speed of 2,700 to 3,800 revolutions per minute. This causes the slider (3) to record and reproduce information on the disk (1). When the disk (1) is stopped, the slider (3) is in contact with the disk (1), and as the rotational speed of the disk increases, the slider (3) begins to float away from the disk (1), and the slider (3) starts to float above the disk (1). When the rotation speed reaches a steady rotation speed, an air film with a submicron thickness is formed between the slider (3) and the disk (1), and the slider (3)
and disk (1) do not make contact. On the other hand, when current is applied to the coil (7), the arm (5) is moved by a certain angle to the floating axis (
6) to move the slider (3) in the radial direction of the disk (1).

[Problems to be Solved by the Invention] Since the conventional magnetic recording device is configured as described above, when the disk (1) is stopped, the slider (
3) is in contact with the disk (1), so if the disk (1) is left stopped for a long time or the surrounding relative humidity is high, it will stick to the slider (3) and disk (1). phenomenon (literature, NTT research practical application report, 2nd
Volume 8, No. 10 (1!379) P, 121,126~
130) occurs, and if the disk (1) is rotated in this state, an excessive load will be applied to the suspension (4), resulting in damage to the slider (3) or disk (1) or deformation of the suspension (4). There was a problem.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a magnetic recording device that can prevent the slider from sticking to the disk.

[Means for Solving the Problems] A magnetic recording device according to the present invention detects a motor current of a spindle that rotates a disk using a detector, and calculates a detection value detected by the detector and a set value. The system is designed to rotate the disk at high speed when the motor current is below a set value.

[Function] The magnetic recording device according to the present invention determines the attraction between the disk and the slider based on the magnitude of the spindle motor current, and if the motor current is larger than a set value, the disk is slightly rotated at a low speed to prevent the disk and slider from interfering with each other. Reduces adsorption power,
When the value falls below the above-mentioned setting value, the disk is rotated at high speed.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, symbols (1) to (5) are the same as those of the conventional device shown in FIG. (1o) is a rotary encoder attached to the end of the motor shaft of the spindle (2) to detect the rotation angle of the disk (1), and (11) is a rotary encoder that counts pulses from this encoder (10) and detects the rotation angle of the disk (1).
(12) is a polarity reversing unit for changing the rotation direction of the disk (1);
3) is a driver that rotates the spindle (2), (14) is a detector that detects the motor current of the spindle (2), and (15) is the magnitude of the motor current detected by the detector (14). This is a calculation unit that compares with the set value.

FIG. 2 shows a flowchart from when the disk (1) activation signal is input until the spindle (2) starts rotating at high speed.

Next, the operation of the magnetic recording device according to the present invention will be explained. The signal that drives the disk (1) to rotate is sent to the driver (
13), first the disk (1) is rotated every minute by a number of
The motor is rotated at a low speed below 0 revolutions, the motor current at that time is detected by a detector (14), and the magnitude of the motor current detected by a calculator (15) is compared with a set value. When the motor current is below the set value, the spindle (2)
starts rotating at high speed. This stage is called the first stage. On the other hand, if the motor current exceeds the set value, the disc (1)
rotates at low speed until the spindle angle exceeds the set value.

In this embodiment, the spindle angle is detected using the spindle (2).
The output of the rotary encoder (10) installed in the control unit (
11), and when the spindle angle exceeds the set value, the polarity inverter (12) turns the spindle (2
) to reverse the rotation. Thus, when the rotation angle of the spindle (2) exceeds the set value, the spindle (2) returns to normal rotation again by the operation of the polarity reversing section (12). The motor current at this time is detected by a detector (14), and when the motor current is below a set value, the spindle (2) rotates at high speed. However, when the motor current does not fall below the set value, the reversing operation of the spindle (2) is repeated several times, and this stage is referred to as the second stage. The above reversal operation is repeated a set number of times, and when the motor current is larger than the set value, the spindle (2) is rotated at a low speed by a fixed amount, and the motor current at that time is compared with the set value. If the motor current is below the set value, the spindle (2) starts rotating at high speed. This stage is called the third stage. Even at this stage, if the motor current is larger than the set value, the device is stopped.

In an embodiment of the invention, a disk (1) and a slider (3
) is determined by the magnitude of the motor current of the spindle (2). If the motor current is larger than the set value in the first stage, the disk (1) is rotated forward and backward by a small angle at low speed, and at this time, the slider (3) is tilted with respect to the surface of the disk (1), and the slider (3) and disk (1
) contact area becomes smaller. For this reason, slider (3)
The film of water molecules between the disk (1) and the disk (1) also aggregates to one side depending on the inclination of the slag (3), reducing the adsorption force. However, if the adsorption force does not decrease in this state and the motor current is higher than the set value, the disk (1) is rotated at a low speed in the third step, and the disk (1) and slider (
3) Generate relative slip between them. Therefore, when relative slip occurs, the friction torque decreases rapidly compared to when adsorption occurs, the motor current can be reduced to a set value or less, and the disk (1) can be rotated at high speed. However, if the disk (1) is severely scratched or the suspension (4) is destroyed when the disk (1) rotates at low speed, the friction torque will be cannot be reduced, and if the disk (1) is rotated at high speed in this state, there is a risk of causing great damage to the disk, but with this invention, the device can be stopped and damage to the disk can be prevented. .

In addition, in the embodiment, the rotary encoder (10) is attached to the shaft end of the spindle (2), but the encoder (10) may be built in the spindle.
As another means for detecting the rotation angle of the disk, the spindle (2
) Alternatively, grooves may be provided on the outer peripheral surface of the disk (1) at regular angle intervals, and these grooves may be detected by a gap sensor or the like.

In addition, in the example, two methods were used to reduce the adhesion force between the disk (1) and the slider (3): one is to cause the disk (1) to vibrate minutely, and the other is to create relative slip between the disk and the slider. Furthermore, although the magnitude of the attraction force between the disk and the slider was determined by the spindle motor current, the same effect as described above can also be obtained by determining by other factors such as deformation of the suspension (4). It will be done.

[Effects of the Invention] As explained above, according to the present invention, the disk is rotated at low speed by a small angle by inputting a signal to rotate the disk, and when the motor current at that time is less than a set value, the disk is rotated at high speed. As a result, the disk can be rotated without the slider and disk sticking together even when the slider and disk are in contact for a long time or when the surrounding relative humidity is high. As a result, the slider's transient This has the effect of preventing damage to the slider, disk, and suspension due to vibration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a magnetic recording device according to an embodiment of the present invention, FIG. 2 is a flow chart until the spindle starts rotating at high speed, and FIG. 3 is a perspective view of a conventional magnetic recording device. In the figure, (ri is the disk, (2) is the spindle, (3) is the slider, (0 is the suspension, (10) is the rotary encoder, (11) is the control section, (12) is the polarity inversion section, (1)
3) is the driver, (14) is the detector, (15)
is an arithmetic unit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A disk that records information, a spindle that rotationally drives this disk, a magnetic head that records and reproduces information on the disk, a slider equipped with this head that scans over the disk, and a suspension that supports this slider. A magnetic recording device comprising: a detector for detecting a motor current of a spindle; and an arithmetic unit for comparing a detection value detected by the detector with a set value, and when the motor current is less than the set value. A magnetic recording device that rotates a disk at high speed. (2) The magnetic recording device according to claim 1, further comprising a control unit that causes the disk to vibrate slightly when the detected value of the spindle motor current is higher than a set value.